[gnome-tetravex] Add reload shortcut.

[Arnaud B. <arnaudb src gnome org>]

commit bab79e0ff3fce11266b0f9b7caec343e0e64f91e
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Fri Jun 12 18:10:36 2020 +0200

    Add reload shortcut.

 src/gnome-tetravex.vala | 10 ++++++++++
 src/help-overlay.ui     | 10 +++++++++-
 src/puzzle-view.vala    |  6 ++++++
 src/puzzle.vala         | 25 +++++++++++++++++++++++++
 4 files changed, 50 insertions(+), 1 deletion(-)
---
diff --git a/src/gnome-tetravex.vala b/src/gnome-tetravex.vala
index 7f888f7..b6d70d4 100644
--- a/src/gnome-tetravex.vala
+++ b/src/gnome-tetravex.vala
@@ -123,6 +123,7 @@ private class Tetravex : Gtk.Application
         { "move-right-r",   move_right_r    },
         { "undo",           undo_cb         },
         { "redo",           redo_cb         },
+        { "reload",         reload_cb       },
         { "size",           null,           "s",    "'2'",  size_changed    },
         { "help",           help_cb         },
         { "about",          about_cb        },
@@ -284,6 +285,7 @@ private class Tetravex : Gtk.Application
         set_accels_for_action ("app.move-right-r",  { "<Shift><Primary>Right"   });
         set_accels_for_action ("app.undo",          {        "<Primary>z"       });
         set_accels_for_action ("app.redo",          { "<Shift><Primary>z"       });
+        set_accels_for_action ("app.reload",        { "<Shift><Primary>r"       });
         set_accels_for_action ("app.hamburger",     {                 "F10"     });
         // F1 and friends are managed manually
 
@@ -901,6 +903,14 @@ private class Tetravex : Gtk.Application
             view.redo ();
     }
 
+    private void reload_cb ()
+    {
+        if (view.tile_selected)
+            view.release_selected_tile ();
+        else
+            view.reload ();
+    }
+
     private void pause_cb (/* SimpleAction action, Variant? parameter */)
     {
         puzzle.paused = !puzzle.paused;
diff --git a/src/help-overlay.ui b/src/help-overlay.ui
index 230c3c4..274270f 100644
--- a/src/help-overlay.ui
+++ b/src/help-overlay.ui
@@ -2,7 +2,7 @@
 <!--
    This file is part of GNOME Tetravex.
 
-   Copyright (C) 2019 Arnaud Bonatti
+   Copyright (C) 2019-2020 Arnaud Bonatti
 
    GNOME Tetravex is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -101,6 +101,14 @@
                 <property name="title" translatable="yes" context="shortcut window">Redo</property>
               </object>
             </child>
+            <child>
+              <object class="GtkShortcutsShortcut">
+                <property name="visible">1</property>
+                <property name="accelerator">&lt;Shift&gt;&lt;Primary&gt;r</property>
+                <!-- Translators: Shift-Ctrl-R shortcut description in the Keyboard Shortcuts dialog, 
section History; undoes all the moves -->
+                <property name="title" translatable="yes" context="shortcut window">Reload initial 
position</property>
+              </object>
+            </child>
           </object>
         </child>
         <child>
diff --git a/src/puzzle-view.vala b/src/puzzle-view.vala
index 6903bb8..4d75d6f 100644
--- a/src/puzzle-view.vala
+++ b/src/puzzle-view.vala
@@ -858,6 +858,12 @@ private class PuzzleView : Gtk.DrawingArea
         puzzle.redo ();
     }
 
+    internal void reload ()
+    {
+        last_selected_tile = null;
+        puzzle.reload ();
+    }
+
     /*\
     * * final animation
     \*/
diff --git a/src/puzzle.vala b/src/puzzle.vala
index 1666381..218b590 100644
--- a/src/puzzle.vala
+++ b/src/puzzle.vala
@@ -745,6 +745,31 @@ private class Puzzle : Object
         _switch_tiles (x0, y0, x1, y1, animation_duration, /* no log */ true, /* garbage */ 0);
     }
 
+    internal void reload ()
+    {
+        if (!can_undo)
+            return;
+
+        unowned List<Inversion>? inversion_item = reversed_history.nth (last_move_index);
+        if (inversion_item == null) assert_not_reached ();
+
+        unowned Inversion? inversion;
+        do
+        {
+            inversion = ((!) inversion_item).data;
+            if (inversion == null) assert_not_reached ();
+
+            undo_move (((!) inversion).x0, ((!) inversion).y0,
+                       ((!) inversion).x1, ((!) inversion).y1);
+
+            inversion_item = ((!) inversion_item).next;
+        }
+        while (inversion_item != null);
+
+        can_undo = false;
+        can_redo = true;
+    }
+
     /*\
     * * save and restore
     \*/